Analysis of the forces and position required for direct laryngoscopic exposure of the anterior vocal folds.

The sniffing position is traditionally considered optimal for direct laryngoscopic examination of the vocal folds. This study examined head and neck positions associated with ideal exposure of the anterior glottal commissure with a variety of laryngoscopes. A prospective investigation was done in 20 patients by comparing the force required to expose the anterior vocal folds by utilizing 3 head and neck positions with 3 different-sized tubular laryngoscopes. The completeness of anterior glottal exposure was rated and the force required to achieve this exposure was measured with a strain gauge. Three positions relating the atlanto-occipital and cervicothoracic vertebrae were analyzed: 1) extension-extension. 2) sniffing: extension-flexion, and 3) flexion-flexion. Head and neck position and laryngoscope size were both statistically significant factors for achieving complete anterior vocal fold exposure. Regardless of the laryngoscope, the number of patients in whom complete exposure could be achieved increased gradually when the position was changed from extension-extension to extension-flexion to flexion-flexion. Complete exposure was inversely related to larger laryngoscope size. According to the data herein, the flexion-flexion position provides the best glottal exposure for endotracheal intubation in those patients who are anatomically predisposed to difficulty in direct examination of the glottis. Because this places the laryngoscope lumen in a vertical position, this position is inappropriate for microlaryngoscopy. The study reinforced the concept that the sniffing position is the optimal position for microlaryngoscopy because it enables the use of the largest-lumened laryngoscope. This facilitates ideal exposure of the anterior vocal folds, which is necessary for phonomicrosurgery.     

Amelioration of ischemia-reperfusion injury in rat intestine by pentoxifylline-mediated inhibition of xanthine oxidase.

BACKGROUND: Intestinal ischemia-reperfusion (IR) injury results in cell destruction, which may be mediated by the generation of reactive oxygen species, potentially toxic metabolites of xanthine oxidase. Pentoxifylline (PTX) possesses a variety of biochemical and antioxidant properties that can improve capillary flow and tissue oxygenation. Because of these combined effects, it has been hypothesized that pentoxifylline would protect against intestinal IR. METHODS: Young adult rats were randomly assigned to one of four experimental groups: IR/Placebo (n = 12) in which superior and inferior mesenteric arteries were clamped for 45 minutes and then reopened; IR/PTX (n = 11) in which IR was induced as in the Placebo group, but with 25 mg/kg PTX at 0, 30, and 60 minutes; No IR/Placebo (n = 12); and No IR/PTX (n = 6) in which placebo and PTX were applied with no IR. Blood and intestinal samples were taken for serial thiobarbituric acid-reducing substances (TBARS; index of lipid peroxidation), for xanthine oxidase-xanthine dehydrogenase ratios, glutathione, myeloperoxidase, and histopathology. RESULTS: Animals in the IR/PTX group had lower TBARS and the least severe histopathologic injury. Xanthine oxidasexanthine dehydrogenase ratios were elevated only in IR/ Placebo (0.67+/-0.22 vs. 0.45+/-0.14 in IR/PTX; 0.42+/-0.22 in No IR/Placebo; and 0.40+/-0.11 in No IR/PTX; p = 0.0009). Reduced glutathione was diminished in IR/PTX animals (38.9 +/-1.35 vs. 46.1+/-7.0 in IR/Placebo; 41.1+/-2.5 in No IR/ Placebo; 43.6+/-1.0 in No IR/PTX; p = 0.048). No differences were recorded in myeloperoxidase levels among groups. CONCLUSIONS: Pentoxifylline ameliorates histopathologic signs of injury and decreases lipid peroxidation (TBARS). Normal xanthine oxidase-xanthine dehydrogenase ratios in the treated compared with IR-only animals imply that the protective effect of PTX is at least partially mediated through inhibition of xanthine oxidase.     

Lack of progress in cardiogenic shock: lessons from the GUSTO trials.

AIMS: We used the GUSTO-I and GUSTO-III databases to evaluate our performance in treating cardiogenic shock patients over much of the 1990s. METHODS AND RESULTS: GUSTO-I (1990-1993) and GUSTO-III (1995-1997) prospectively identified all patients with cardiogenic shock complicating acute myocardial infarction. Demographics, clinical presentation and outcomes for cardiogenic shock patients in the two trials were compared. Only patients enrolled with cardiogenic shock in countries common to both trials were included in these analysis. The 695 patients with cardiogenic shock in GUSTO-III were compared with the 2814 patients with cardiogenic shock in GUSTO-I. GUSTO-III patients were older (P=0.0001) and more likely to be diabetic (P=0.009) and hypertensive (P=0.025). They had a higher Killip class (P=0.002) and significantly greater index anterior infarction than cardiogenic shock patients enrolled in GUSTO-I. Time to treatment, presentation heart rate, and diastolic blood pressure were similar; however, systolic blood pressure at presentation was higher among GUSTO-III patients (P=0.002). Rates of coronary angiography, pulmonary artery catheterization, and mechanical ventilation declined in GUSTO-III compared with GUSTO-I (P=0.001); rates of angioplasty and bypass surgery were similar. Cardiogenic shock mortality in GUSTO-III was significantly higher than in GUSTO-I (62 vs 54%, P=0.001), as were rates of reinfarction (14 vs 11%, P=0.013) and recurrent ischaemia (35 vs 27%, P=0.00001). Mortality at non-U.S. sites (68 and 64%) was higher than at U.S. sites (53 and 50%) in both GUSTO-I and GUSTO-III studies, respectively. Angioplasty, bypass surgery, and balloon pump rates were lower for non-U.S. patients. CONCLUSIONS: Cardiogenic shock continues to be associated with high mortality in thrombolytic-treated patients. Lower mortality observed in the U.S.A. supports consideration for percutaneous and surgical revascularization.     

氟尿嘧啶白蛋白微球的制备工艺研究

目的：制备具有肝靶向意义的氟尿嘧啶白蛋白微球。方法：采用乳化热固化技术制备氟尿嘧啶白蛋白微球。以粒子（粒径＜1μm)分布百分数、载药量、包封率为指标,设立总的优化指数,选择固化温度、固化时间、搅拌速度、油／水体积比为因素,每个因素各取4个水平,按L16（4^5)正交设计优化制备工艺。结果：四个因素中,固化温度对总优化影响最大（P＜0．01）,其次是固化时间、搅拌速度（P＜0．05）,而油／水体积比则几乎没有影响（P＞0．05）。经过优选制得的Fu-BM,扫描电镜观察呈规则球形。粒径范围为0．15－0．98μm,跨距为0．65,平均粒径0．56μm。载药量、包封率分别为6．13％、90．38％。结论：本法工艺简便,稳定,具有应用前景。     

Results of surgical closure of isolated secundum atrial septal defect

Methods A retrospective analysis of all patients undergoing surgical closure of an isolated secundum atrial septal defect, at the Postgraduate Institute, Chandigarh between January 1974 and June 2000 was performed. 740 patients were divided into two groups. Group I. Included 435 patients under 20 yrs of age (223 male), 315 (72%) were asymptomatic, 265(61%) were in sinus rhythm. Group II. included 305 patients between 21 and 53 years (96 males), 27 patients (9%) were asymptomatic, 102(33%) were in sinus rhythm. Cardiopulmonary bypass with fibrillatory arrest and/or cold blood cardioplegia were used. In group I 291 patients (67%0 and in group II 64 patients (54%) underwent direct closure of the defect. In the remaining a patch was used for closure. Results There was 1 early death in group I (0.2%) and four in group II (1.3%) 96% of symptomatic patients in group I and 87% of patients in group II were improved. There were no instances of residual shunt. Follow up ranged from 6 months to 25 years (mean 8.3 yrs) and was 89% complete. Conclusions Closure of isolated secundum ASD is best performed before the patient attains adulthood.